1. Field of the Invention
The present invention relates to a sheet-feeding mechanism employed in a printer, or the like and transferring sheet between rollers.
2. Description of the Related Art
A conventional sheet-feeding mechanism comprises a pressing member of predetermined weight which presses upper rollers carried by a shaft, so as to prevent the shaft from curving despite the thickness of a sheet to be fed. Such a pressing member is disclosed in e.g., Published Examined Japanese Utility Model Application (PEJUMA) No. 59-25788. However, it is likely that the pressing member will increase the friction between the sheet and rollers more than necessary. If the friction between the two is too large, the print side of the sheet may be stained when ink is transferred onto it. In addition, if the pressure applied to the shaft is not uniform, the sheet may not be fed in a stable manner.
The sheet-feeding mechanism disclosed in Published Examined Japanese Patent Application (PEJPA) No. 56-23796 employs deformable rollers formed of an elastic material. Since such rollers prevent a shaft from curving, they enable a sheet to be fed with high accuracy. In general, however, deformable or elastic rollers have a large friction coefficient, so that the problem that the print side of a sheet is stained with ink remains unsolved.